Internal combustion engines, such as those found in vehicles, may utilize a cooling circuit to reduce over-heating. This may be achieved by a combination of engine oil cooling and liquid coolant cooling.
Liquid coolant absorbs excess heat from combustion and transfers the heat into the air or cabin of the vehicle via respective heat exchangers, such as a radiator and heater core. However, liquid coolant is isolated from the combustion chambers in order for ignition to occur; heat is therefore exchanged via conductive metal passageways surrounding the combustion chambers. These isolating passageways may be referred to as the water jacket. Coolant is accelerated through the engine by way of a fluid pump before entering the water jacket; this closed coolant circulation pathway referred to as the coolant circuit. Engine oil may undergo a similar heat exchange process within a separate circuit wherein oil is accelerated by an oil pump coupled to an oil injector within the engine block. This oil injector deposits oil on the underside of the piston where heat is absorbed and then deposited via a heat exchanger.
Conventionally, coolant fluid pumps are mounted onto the engine block surface and coupled to the engine water jacket. The high-pressure die casting manufacturing method used for engine production relies on the coolant passageways being linear. One way in which coolant exiting the coolant pump may be coupled to the water jacket using linear paths is by the creation of a cavity on the outside of the engine block sealed by a cover plate. In this way the coolant path can change direction without leaving the engine block. Conventional coolant cavities have a water pump outlet that opens into one side of the coolant cavity, and another side that is open to the water jacket. However, the inventors recognized that this abrupt change in coolant flow direction creates losses in fluid flow control.
This issue may be addressed by creating a coolant cavity configuration and cover plate to direct the flow of coolant from the water pump outlet port to the water jacket inlet port down a slope, thus decreasing flow control losses. In one example, a system for engine cooling comprises: a cover plate for a coolant passage, the plate including a coolant outlet port displaced away from a coolant inlet port, and a plurality of oil ports; and a coolant cavity, covered by the cover plate, within the coolant passage and coupled to a fluid pump and a water jacket.
Various additional advantages may be achieved in some embodiments. For example, the cover plate may enable reduction of the number of engine block components while meeting the increased demand on the cooling system by integrating a port for engine oil to enter the engine block via an attached valve. In doing so, the proximity of the engine oil and coolant is reduced and undesired heat absorption into the cooling system reduced to provide more effective cooling. The system may also reduce the need for an additional port and valve arrangement to pass oil into the engine block. Further, by actuating the oil valve in response to temperature sensors within the oil circuit, engine heating to a desired operating threshold can be expedited. Additional ports optionally incorporated into this cover plate also provide a solution to the distribution of oil and coolant to turbochargers, EGR, and other systems.
It will be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description, which follows. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined by the claims that follow the detailed description. Further, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.
FIGS. 2, 3, 4A, 4B, 5, 6, 7, 8, 9A, 9B, and 10 are drawn to scale, although other relative dimensions may be used.